This invention relates to a method and apparatus for controlled programmable electronic winding of yarn in the textile industry. More particularly, this invention relates to a method and apparatus for yarn winding in which the geometry of a yarn package is variably controlled electronically according to a predetermined program. Still more particularly, this invention relates to an automatic yarn winding system which is electronically programmable to achieve pre-programmed density profiles in a yarn package which are uniform in shape, density, and weight averages between take-up packages made of the same yarn. In another aspect, this invention relates to the application of such winding to warping for yarn dyeing on beams, to beams thus warped using such techniques, and to the novel geometry of dyeing beams made possible by such techniques.
In the textile industry, yarn is generally packaged for various steps in textile processing as a plurality of wraps of yarn disposed about a core. The ideal characteristics of a package of yarn usually depend upon the end use of the package and the characteristics of the yarn so that yarn packaged for weaving or warping may be packaged differently than yarn intended for dyeing. By way of example, a package of yarn for weaving should usually have a mild wrap angle about the core and the yarn-to-yarn friction should be minimized during unwinding. Such a weaving package should also usually be as heavy as possible and include a workable transfer tail in order to minimize labor. In contrast, a package of yarn destined to be dyed should be porous in order to allow the dye liquor to flow through the packaged yarn with a minimum of resistance and a resulting minimum loss of pressure. Thus, a number of machines and devices have been developed for winding yarn in such packages.
Generally, such winding machines have been of two types, i.e., conventional winding machines which generally include either a grooved drum or a cam guide for the yarn, and so-called precision winding machines which include a propeller driven with a constant wind ratio. A particularly suitable winder assembly wherein the winder is controlled primarily mechanically was available from Sharer Textile Machine Works, Ltd., Switzerland, which is now part of the SSM Corporation of Switzerland. In that winder, yarn from a supply package is provided through a mechanical tensioner which has a fixed tension to the propeller to be wound at a fixed, constant wind ratio on a package. To vary the wind ratio, a mechanical linkage having a swivel arm is adjusted. In addition, the back pressure on the yarn exhibited by the back pressure system of the machine can also be adjusted. However, such adjustments can only be made mechanically when the machine is not running, and there is no effective way to adjust the geometry of the wound package during operation. Such shortcomings are significant not only from a labor and production standpoint, but also from the viewpoint of the end use of the package.
For yarn dyeing, for example, a precision wound package is more likely to permit an easier flow of dye liquor from the interior of the core through the packaged yarn to the exterior of the yarn package than a random wound package of yarn. Unfortunately, even yarn packages which are precision wound using conventional techniques, such as by the Scharer winder, do not consistently produce a controllable density profile for the yarn package. In random winding, for example, the yarn is wound over the circumference of the support by tangential friction at an angle determined by the constant groove pattern in the drum. As the package diameter increases, the length of yarn delivered for a wrap also increases so that the distance along the support between the beginning and the end of a wrap must also increase to maintain the ratio constant. Therefore, so-called "ribbons" are formed when successive layers of yarn accumulate on top of or adjacent one another. The yarn density of such ribbons is higher than that of the package, thus interfering with liquor flow through the yarn mass during dyeing. While mechanical expedients have been tried with some success, the density of the yarn package is not readily mechanically controllable during random winding.
In contrast, during precision winding, package density near the core or support is quite low due to the slow starting speed of the winding machine, and then increases slightly as the package diameter increases. However, little attention is generally paid to package density because of the inconvenience and difficulty in mechanically adjusting the mechanical features of the winding machine as mentioned above.
The foregoing background is presented in the parent pending application mentioned above. Another problem which is assisted by the features of the invention relates to warping with progressively increasing tension between the inside and the outside of a dye beam. Yarns also commonly dyed on beams, especially for woven styling in fabrics that contain dyed yarns in the warp such as shirting materials, especially oxford fabrics, which usually consist of dyed yarn in the warp and greige yarns in the filling. Other fabrics that use beam dyed yarns are striped towels, mattress ticking, striped shirting, pajama fabrics, and all types of fabrics that are woven with jacquard patterns. Except for a few shades or styles, those fabrics are usually produced in short yardages, therefore requiring short manufacturing runs.
Dyeing on beams is economical when compared to dyeing in package form, as described above. However, the manufacturing sequence differs between package dyed yarns and beam dyed yarns. The package dyeing process consists of more production steps, which result in a higher cost for the finished product. Quite often, when preparing to weave short yardage, yarns have to be dyed on full-size packages and backwound onto smaller packages suitable for the length of yarn needed for the warp. The same condition applies when the stripes across the width of the fabric consist of a small number of ends. The total weight of these ends is relatively small, and the yarns are dyed on full-size packages and then backwound to a small number of packages. Backwinding is an added function; it also increases the hairiness of the yarn and the amount of wasted yarn.
It is a continuing problem in connection with the beam yarn dyeing industry to address the channeling of the dye liquor flow. This defect, generally referred to as a blow-up or blown beam, occurs when the dye liquor finds a less dense area of yarn and flows through that path of least resistance instead of flowing uniformly throughout the beam. In the main, little attention has been given to the problem of blown beams since the industry considers blown beams to be strictly a problem for the dyer to be solved in the dyehouse and not in the geometry of the beam itself. That blow-up of the beam is most likely to happen where the thread density factor is the lowest. The thread density factor is calculated by taking the square root of the number of ends divided by the cotton count.
In the art, a typical dye beam has the following construction characteristics: (1) an outside flange diameter of about 31 inches; (2) a core diameter of 23 inches; (3) a beam width of about 56 inches; and (4) a maximum yarn weight of 275 pounds. A striking feature of this geometry is the core diameter which leaves only four inches of radial distance for the yarn layer thickness. Despite this significant sacrifice in productivity, beams continue to blow, especially when they are made of two-ply yarns, as commonly used in toweling. Thus, a significant and continuing problem in the beam dyeing art is to improve productivity while not causing increases in beam blowout.
Thus, it is an overall objective of this invention to provide controlled electronic programmable winding for yarn packages. Such an invention would be useful to increase the productivity and the quality of yarn dyeing by controlling the density profile for the yarn package with favorable results. For example, a consequence of a low pressure drop across the yarn package during dyeing is that the yarn mass in the dyeing machine can be increased, thereby effectively increasing the yarn capacity and dyeing capacity of the dyeing machine. Moreover, the package geometry can be improvedly controlled according to the invention.
It is an additional overall objective of this invention to apply progressively increasing tension uniformly across the width of a warp on a beam to improve the process of beaming.
It is another general objective of this invention to provide a method for controlled electronically-programmed winding for packaging yarns.
It is still another objective of this invention to provide a method and apparatus for winding yarn according to a program implemented through an electronic apparatus to provide a predetermined density profile to the packaged yarn.
It is still another objective of this invention to provide a method and apparatus for winding yarn on a beam according to a program implemented through an electronic apparatus to provide a progressively increasing uniform tension across the width of the warp and to increase the tension gradually as more yarn is warped around the beam.
It is still another objective of this invention to provide a method and apparatus for controlling yarn package geometry by electrically controlling the tension on the yarn during winding according to a predetermined program to provide a particular geometry and density profile to the yarn package.
It is still another objective of this invention to provide a method and apparatus for controlling yarn package geometry and its density profile by electronically controlling, by a predetermined program, the tension on the yarn.
It is yet another objective of this invention to provide a novel beam configuration which has a greater beam aspect ratio than prior art beams while permitting dyeing of greater amounts of yarn without increasing amounts of blowout of the beam during liquor dyeing.
It is still another objective to improve the consistency of K/S values across the length of a beam by progressively increasing tension along the length of the beam.
These and other objectives of this invention will become apparent from the detailed description of the invention which follows, taken in conjunction with the accompanying drawings.